Engine



Feb, 5 1924. 1,482,796y K. o. KELLER Feb. s, 1924-. 1,482,796 K. O. KELLER MNH' uw "un IllIll l' 10 wei/@.14 M

L agg.,

vFeb..A 5 1924.

K. o. KELLER ENGINE Filed July 8, 1920 3 Sheets-Sheet 3 l 1,482,796 PATENT oFFlcE.'

KARL OTTO KELLER, OF SUNDERLAND, ENGLAND, ASSIGNOR OF ONE-HALF TOB'OBERT PILE DOXFORD, OF SUNDEBLAND, DURHAM, ENGLAND.

ENGINE.

Application iled July 8,

To all rwhom t may concern.'

Be it known that I, KARL Or'ro Kramm,

a citizen ofthe `Swiss Confederation, re-v lotted to the respective `pairs of pistons,

y 1909 (Fuuaar) and' 130,7

and main connecting-rods each such rod operatively connecting the piston that is at. one end of each line with one of the cranks aforesaidythe cranks have angular advance one in relation to the other and-the pistons in each cylinder move in opposite directions therein because, between the piston appropriated to each crank as aforesaid in one cylinder and that one ofthe pistons in the other cylinder whichV is not so directly crank-controlledg'there is a diagonal cross: connection. Examples of engines of this type may be found in the specifications of prior British Letters Patent: No.. 6,102 of 67 (Cammell Laird & Co. td. & ors.).

The diagonal cross-*connection aforesaid has been rlgidly connected' at its-opposite way of ends to the -respective pistons b in such cross-heads, the lower cross-hea cases having served as the main cross-head,

that is to say as the cross-head to which the main connecting-rod has been connected.

Out of this construction difficulties have arisen. For example, the cross-head shoes or bearing surfaces of the main cross-heads having had to take not only the thrust in one plane due to the obliquity of the main connecting-rod, but also the diagonal thrust in another plane at right angles to the former due lto the diagonal cross-connection aforesaid, have been subjected to wear upon two faces at right angles to each other. For this reason the said faces have been fiat and as they have been formed upon parts of the same main cross-head, it has been dieult to maintain the latter in the perfect alignment in relation to the cylinder axis which is so essential in practice. The cross-head faces taking the thrust due to the Obliquity of the main connecting-rods have moreover already 1920. Serial No. 394,681.

had to be placed far apart in order to accommodate in betweenv the1n` on the same cross-head the attachment of the diagonal cross-connections aforesaid to that crosshead.- This has resulted in a cross-head whose dimensions from front to back have been so great that its linear expansion when it became hot. was considerable, thereby necessitating considerable working clear. ance between the aforesaid cross-head faces and the contiguous guide faces which `have been rubbed thereby, otherwise such expansion from front to back could not have been accommodated.-

Moreover, the said diagonal cross-connections have not only. heretofore beenA ri idly attached by their upper and lower en sto the pistons, but they have been duplicated, one extending down the front ofthe engine and the other opposite to it down theback, vand they have not each been arranged at the same distance from the fore-and-aft ,planecontaining the axes of the four pistons. Consequently any elongation of thev two rods which may have occurred has brought about, because of the lack of symmetry in their. disposition and sometimes because of differences in the material of which they are made, a slewing of the 'main cross-heads, and therefore the cross-head and guide wearing-surfaces Ahave worn into a curved form instead of remaining flat.

Moreover, engines of the type above defined have lacked accessibility so far as accessv to the main cross-heads and the conif necting-rod Ibearings is concerned, owing to the fact that the columns forming supports for the cylinders have been made to afford guiding surfaces not only for the shoes `bearing the thrust from the diagonal crossconnections aforesaid but also for the main i links may individually he of ytwin construe# tion, the first link in the plane of and approximately parallelv with the axis offene of the pistons, and jointed` to.l that piston,-

the second link being jointed to the first link and the other piston. This jointed linkage is combined with a guiding device which constrains the joint connecting the first and second links to move in a line that is parallel to the piston-strokes, when it reciprocates with the pistons. This guiding device is quite distinct from the guides' for the main cross-head. A linkage thus ar-i ranged and guided cannot impart to the main cross-head any side thrust arising out of the angularity of the diagonal link (the second link), such thrust being intercepted by the guiding device aforesaid. Thus the main cross-head is subjected only to wear of such kind as that which comes upon it by reason of the angularity of the main connecting-rod, thrust from the linkage being only a negligible amount or else being balanced as hereinafter described, and being in either case received on the vertical faces on which the ordinary horizontal resultant of the angular thrust of the main connecting-rod is exerted and not, as in previouslyknown constructions, giving anotherhorizontal resultant at an angle to the former.

Preferably the joints which are employed to connect the linkage with the pistons are spherical whilst the joint which connects the first and second links to one another can be either hinged, or spherical. If it be hinged it should be so constrained that whilst it is compelled to move in its reciprocation with the pistons, in a line parallel thereto, it can shift laterally of such a line, into a new one parallel with it, should `the cross-head arms or the linkage or both alter slightly in length, or should the beam referred to in the next paragraph alter in effective length.

AWhen the second link aforesaid is of twin A construction it can be combined with a'beam )ivoted to the piston to which said second link is connected, the beam-pivot having an axis transverse to that of said piston. and the beam having at its ends spherical bearings constituting parts of the pivotalcon- 'nection of the second link with the piston.

ln such a case, any difference in elongation lzetween the two sides of a twin link or of theI companion link to which it is connected, merely results in slightly tilting the beam about the beam-pivot and there can be no tendency to any slewing of the main crossheads.

The arms which project from the main cross-heads and form part of the pivotal connection of the first llnk aforesaid to the piston corresponding with a cross-head, are lon arms, and therefore the slipper or other gui es which constrain said main cross-head are according to this invention ut nearer to the axial line of the correspon ing piston than are the ends of the arms. Therefore, should any expansion of the cross-head take place it is only the expansion of that short l ferred to the second links are of twin construction, the opposite sides of each linkare made to` be equidistant from .the plane of the axis of the pistons, and` one second link has its elements spaced apart from one another widely enou h to permit the companion twin link to wort in the space thus afforded. Thereby even loading of the elements of the second link is secured.' Such even loading has not been possible, in the known type of engine in which the elements of the links have not been equidistant from the plane of the axis of the pistons. Where the links are twinned the parts thereof may be spread a little as in Figure 3 hereinafter described. Being equally spread, i. e. being symmetrically set relatively to the fore and aft plane containing the axis offthe pairs of pistons, such side thrusts as this disposition of them causes upon the main cross-head cancel one another.

Further, in an engine of the type described the front columns which form supports for the plurality of cylinders in which the crossconnected pistons work, are set further apart from one another than'are the axes of thel pairs of pistons, and are combined with back columns and main cross-head guides supported by said back columns, and combined also with guides which constrain the joint connecting the aforesaid first and second links, which latter guides are at a level different from that of the main crosshead guides. This makes the two sets of guides independent of one another, enables the main cross-head to bekept in proper alignment with the piston to which it is appropriated, and also makes the main crossheads and connecting-rod bearings easily accessible. The adjustment for wear of the guiding device which-constrains the joint connecting the first and second links is quite independent af any adjustment for wear of the main cross-head, for the latter is free from the need for any adjustment save that l Figure 4 is a central vertical section I through the left-hand cylinder in Figure 1 looking from the left.

Like reference characters indicate like parts throughout the drawings.

In the particular construction illustrated in the drawings, the bed-plate of the engine is Shown at 10 and it is provided with front columnsll, and rear columns 12 to support the cylinders andother parts of the engine. As illustrated, the engine has four working cylinders indicated respectively at 13, 14,

15 and 16. These are arranged vertically and in pairs, 13, 14, constituting one pair, and 15, 16, constituting the other pair. It is only necessary to describe in detail one such'pair of cylinders since the two pairs are duplicates of one another.

Considering then the two cylinders 13, 14, these are parallel with one another and each contains a pair of pistons 17, 18 and 19, 2O reciprocating therein. The crank-shaft 21 has a separate crank-pin for each cylinder as shown at 22, 23, one of these cranks having an angular advance in respect-to the other one. As illustrated, one crank is set- 180 from the other. The crank-pins are coupled by connecting-rods 24, 25, respectively to the main cross-heads indicated as a whole by the reference 26, and these main cross-heads are coupled respectively to the lower pistons of the pairs .(the two pistons in each cylinder being the pairs referred to.) by rods 27, 28 respectively, which are rigidly secured to the pistons. f

The pair of cross-heads 26, are shown separately in plan, in Figure 2. Each crosshead comprises a central block 29 whereto the piston rod (27 is connected, and laterally-projecting pins 30 to receive the forked ends of the connecting-rod (24). This main cross-head is also provided with a bearingface 31 of arcuate section to co-operate with a guide 32, See Figures l and 3, in the usual manner, this guide taking up the side thrust due to the Obliquity of the main connectingrod.

These main cross-heads 26 are moreover provided with arms projecting laterally from thcm at right-angles to the )ins 30 as shown at 33, 34 respectively, and t ese arms are of such length that their'ends 35, 36, (which for the pur )ose hereinafter described are preferably sp erical) are situated at a greater distance from the axis of the pistons than is the slipper or bearing-surface 31. The arm 34 therefore projects through a slot formed in the guide 32 for the slipper 31.

As above-stated, it is the object of this at the outermost end of its stroke.

invention to provide an improved construction ofv the diagonal cross-connection between the pairs ofpistons in two adjacent cylinders, that is to say, of the connections whereby the pistons 17 and 20 are caused to reciprocate in unison and the other two pistons 19, 18, are also caused to reciprocate in unison with one another. A jointed linkage is used to connect the pistons and it comprises. a first link 37 and a second link 38. The first link 37 is in pivotal connection with the piston 17 by its engagement at its lower end with the spherical end 35 of the arm 33 of the-main cross-head aforesaid. As above-'stated this main cross-head is rigidly secured 'to the piston, so that 'considered as a linkage the said first link 37 is pivotally connected to the piston 17. This joint will be hereinafter referred to as the .fi-rstpivwhich is a pin joint or hinge and is indicated by the reference 39. The link 38 is connected at its upper end by a pivotal connection, which is preferably a spherical joint, as hereinafter described, to the piston 2(7); this joint is indicated by the reference character 40 in Figure 1. i

As shown in Figure 4, the cylinder 13 is` provided with air-inlet ports 70, so positioned as to be opened by the piston 17 when The air is supplied to these ports through a chamber 71 which surrounds the lower part 72 of the water-jacket. The fuel is injected through an opening 76 at the middle of the length of the cylinder under'the control of any suitable valve 7 5. The exhaust ports 73 are situated at the upper end of the cylinder so as to be uncovered by the piston 18 when at the outermost end of its stroke, and theycommunicate with an annular passage 7 4 which conveys the gases to the exhaust, outlet to atmosphere.

lt will be seen, therefore, that the linkage comprisesl a first link 37, a second link 38 and three pivotal lconnectionsyt-he first at the cross-head 26, the second between the two links at 39 and the third between the second link and its piston at 40.

The joint 39 which is a hinge or pin-joint tion relatively toits movement, is atright'-l angles to the plane of the guide 32,.which`- takes the lateral thrust of the main connecting-rod 24: Moreover, it is located at a different level in the engine structure.

The

' linkages hereinbefore described so that each main guides 32 are supported on the main back columns 12 aforesaid, for example being made integral with portions thereof, as shown in Figure 3, and being supported as to their lower ends vby a transverse horizontal 'beam extending 'between the back co1- umns 12. The columns 11 and 12 are connected together at their upper ends by bridge-pieces, and the auxiliary guides 44 are supported from this bridgepiece in any taken up on the spherical joint 36 at the lower end of the link 37 without disturbing the alignment of the main cross-head-26 with the piston 17 to which it is appropriated.

Further, it will be seen, as above stated,

Vthat any thermal expansion of the outer end of the arm ,34 of the cross-head 26- does not affect the location of the cross-head with respect toits guide 32, since thatlocation can be varied only by the expansion of the Y comparatively short length between the axis of the cross-head and tie slipper 32. The expansion of the outer end of the arm 34 merely causes the first link 37 to be thrown out. of alignment, and such tilting .of the linksis accommodated by the spherical joint 36.

It is preferred to construct the jointed link is of twin formation, the two elements Aof each link lying at opposite sides of the i piston.- That is to say, in Figure 1, one element of the rst link 37 is on the front of the cylinder 13 and its companion element 37 is in a corresponding position behind thc cylinder. That is to say they aresituated in the plane of the axis of the piston to which they are appropriated and at opposite sides of that piston. This is shown most clearly 'in Figure 3. The construction of linkage illustrated in Figure 1 as applied to the cylinder 13 is duplicated and it is for this reason that the cross-head 2G shown in Figure 2 is provided with the two laterally-projecting arms 33, 34.A It is to be understood, however, that the slipper -31 is not an element of the special linkage and it therefore is not duplicated. This slipper accomplishes the ordinary functlons of a main cross-head which is to accommodate the lateral thrust due to the Obliquity of the main connecting-rod.

The second link 38 of the linkage is also duplicated as shown in Figure/3 at 38,38 and the connection of this twin second link, at its upper end to its piston is shown'most clearly in Figure 3 in the case of the piston 18. It will lbe appreciated vthat the twin links 38, 38l are connected lto the piston 20, but their connection lies behindthe piston 18 in Figure 3 and is thereby concealed. The connection of the corresponding twin elements 50, 51 arehowever shown. Each of these links is coupled bya spherical joint 52 to a beam 53 which is pivoted to the piston by a pivot having an axis transverse to that of the piston The pivot pin is shown at 54, being in this construction of engine horizontal and lying in the plane of the axes of two co-operating cylinders. The pivotpin itself is mounted on, or secured to a slipper 56 which slides upon a guide face 57. This slipper 56 is rigidly secured to its appropriate piston, and the guide 57 takes up the lateral thrust due to the Obliquity of the second link. By this constructlon any difference in elongation between the two4 elements of a twin link, from any cause,

.merely results in slightly tilting the beam 53 on its pivot. This tilting movement is fully accommodated by the spherical joints 52 and imparts no slewing' or twisting tendency to the main cross-head, as has occurred 1n previous constructions of cross-connected engines of this type.

The two elements 38, 38 of the second link above-described are similarly connected to a beam 55. The two beams 53, 55, are eachsupported centrally on their slippers and pistons, or in other words, thetwo elementsl of a second link are equidistant from the axis of the piston to which they are connected. Even loading of the two elements of each second link is thereby secured, this not having been possible vin engines heretofore constructed. It ywill be seen llnFigure 1 that on each side of the engine,

that is to say the front and back, the elements of the second links, for example 38, 50, cross one another and to accommodate them, one of the beams 55 is made longer than the other beam 53. Preferably the lateral spacing apart of the hinge joints 39 at their lower ends, as shown in Figure 3, is such that each of the elements 38,f^50 is equally inclined to the vertical, but on opposite sides thereof. All the joints 39 with their slippers 42 on the front of the engine can therefore lie in one plane and similarly those at the back of the engine can all lie in one plane, such planes being parallel to the vertical plane containing the axes of all the cylinders. y

It will be seen that with this construction l easily accessible.

the various slippers and their guides are all rl`he main cross-heads 26 are directly accessible from the front of the engines betweenv the front columns l1 which are spaced apart for this purpose, as abovedescribed; similarly the slippers 42, 43, with their guides 44, 45 are also accessible, although for-convenience they are covered by a detachable cover-plate which is shown in position at the right-hand side of Figure l. Finally, the top-most slippers 56 with their guides 57 are merely covered by a detachable cover 6l which is also shown in position on the right-hand side of Figure 1 and in Figure 3, this cover being slotted as at 62 so that the spherical ends of the beams 53, 55 can project through it. The result of this is that the three pivotal connections in the linkage are also readily accessible for inspection or adjustment.

What I claim as my invention and desire to secure by Letters Patent is 1. In an engine of the type described, the combination of pistons, jointed linkage cross-connecting two pistons which reciprocate in different parallel lines and comprising a first link which is in the plane of the axisof and approximately parallel to the axis of one of the pistons and jointed to that piston, a second link jointed to the first link and to the other piston, and gulding means which constrains the joint connecting the first and second links to move in a line parallel to the-piston strokes of that one of the two pistons with which the first link 1s 1n immediate connection whenit reciprocates with the piston.

2. A construction according to claim l wherein the guiding device which constrains the joint connecting the first and secondV links to move in a line that is parallel to the piston-strokes vof that one of the two pistons with which the first link is in immediate connection -when it reciprocates with the pistons, comprising the combination of a slide-block forming part of the joint, and a flat slide-bar, the latter in a plane perpendicular to the plane containing the two links and being wider than the slideblock in order that the slide-block may be free to adjust "itself across the line wherein it is reciprocated-by the pistons. n

3. In an engine of the type described, the combination of a plurality of pistons, a jointed linkage cross-connecting two of said pistons which reciprocate in different .parallel lines and com rising a rst link that is in the planev of the axis of and approximately arallel to the axisvof one of the pistons an link whic is jointed to the first link and jlointed to that piston. A second to the other piston, and guiding means which constrains the joint connecting the first and second links to move in a line parallel to the piston-strokes of that one of the-two pistons with which the first link is in immediate connection when it reciprocates with the pistons, a main cross-head to which one end of a main connecting-rod is attached, arms projecting from said main cross-head and forming part of the pivotal connectionof the first link aforesaid to the piston corresponding with the cross-head, and guides which constrain said main cross-head, situated nearer for the purpose described, to the axial line of the corresponding piston than are the said ivotal connections.

4. n an engine of the type described,the

combination of a plurality of cylinders andpairs of pistons which latter reciprocate in different parallel lines, front columns form- Y ing sup-ports for the cylinders in which the pistons work, the said front columns being set apart wider from one another than are the axes of. the pairs of istons, back columns, main cross-head guides supported by .two pistons *which reciprocate in diierent parallel lines and comprising a first link and second link, the first link being a link that is in the plane of the axis of and approximately parallel tov the axis of one of the pistons and jointed to that piston, each l.said back columns, a first link which is in second link being a link of twin construction that is jointed to the first link and to the other piston, the opposite sides of each second link being equi-distant from the plane of theaxis of the pistons and one of the second links having its elements spaced apart from each other widely enough to permit the other twin link to work in the space thus afforded, and guiding means which' constrain vthe jointsd connecting the firstl and second links to move in a line parallel tothe pistonstrokes of the two pistons with which the first links are in immediate connection, when the said joints reciprocate with the pistons.

In testimony whereof I aflix my signature.

KARL OTTO KELLER. 

